Former TARP watchdog has leeway to dig into bank’s past dealings with Americans

ZURICH—If Credit Suisse Group AG thought pleading guilty to a charge of aiding U.S. tax evasion and agreeing to big fines last year would firmly put the issue behind it, the Swiss bank wasn’t reckoning on Neil Barofsky.

As part of last May’s settlement with U.S. authorities, New York’s banking agency planted Mr. Barofsky, a former federal prosecutor, inside Credit Suisse as a monitor, with broad license allowing him to dig into the bank’s past dealings with Americans and its compliance policies.